I have a Cooper S 2007 1.6 petrol (80k miles) and I think N14 engine. I'll list the recent error codes below and then detail sympotms and recent work (I have a pretty basic OBD reader).

Codes
Currently present:
P2187 - System Too Lean at Idle (Bank 1)
P0301 - Cylinder 1 Misfire Detected

Codes that were on and then disapeared:
P3091 - Fuel Pump Control Circuit Malfunction
P2177 - System Too Lean Off Idle (Bank 1)

Symptoms:
Initially poor starting was the first problem, with several attemtps needed. It would idlde really rough, not quite 'catching' before dying. Then when warm it ran well and started again, with some minor backfiring.

Now the current codes have come on (p2187 and p0301) and it has lost power. The engine is juddery and wont let me go over 50mph, which might be a combination of limp mode and whatever the issue is. Previously I experienced limp mode and it was not as bad as this and did not have the judder to it. This happened on the way somewhere, so I have come back and grounded her for the time being. Also the oil light has been popping on when I slow down, and seem consistent when at rest idling.

Work that has been done recently:
Changed the coolant temp sensor and garage repaired some wiring and replaced the plug there. They could not diagnose the poor starting, as no error codes. They also changed the spark plugs and tried new coil packs, which made no difference. It seems car was not looked after or serviced well, and plugs v carbed up. They suggested the VANOS could be a next step, so I have one to fit now. But now with the recent codes and increased problems, it seems it might be more serious than VANOS. HPFP seems a consisitent issue with these cars?

Other work probably not related:
I had the oil cooler change as there was a serious oil leak and coolant leak. I then changed the rocker cover myself as this was leaking badly, and bought a new coolant cap. Mainly this has slowed things in terms of leaks, but not completely.

Any advice welcome!

 

A scan tool that can read BMW fault codes would almost surely provide additional more detailed information.
The $7 Car Scanner Pro phone app is adequate.

Start by looking for intake air leaks and a leaking PCV diaphragm as well as by measuring the fuel pressure at the rail with a pressure gauge. If you have the N14 engine, Car Scanner Pro is another option for reading the fuel pressure.

 

Cool thanks for the advice. I don't have the equipment for the pressure test, but seems a good idea to get a garage to do first before spending all the money on a pump.